Shedding light on dark DNA Most textbook definitions of evolution state that it occurs in two stages: mutation followed by natural selection. DNA mutation is a common and continuous process, and occurs completely at random.
The average adult only eats 15 grams of fiber per day. Women need 25 grams of fiber per day, and men need 38 grams per day, according to the Institute of Medicine.
The national fiber recommendations are 30 to 38 grams a day for men and 25 grams a day for women between 18 and 50 years old, and 21 grams a day if a woman is 51 and older.